A document scanner moves a document through a transport path and creates a digital image of the document as it moves. The processor for the document scanner has preset document characteristics and the operator must select functions and features to accommodate the specific requirements for a particular type of document. Alternately, the scanner may default to less efficient settings that will process all documents since scanners are not typically programmed with specific requirements on a document-by-document basis.
The preset characteristics include document characteristics such as size, weight, texture; and specific application requirements such as resolution and imaging mode, color, simplex, or duplex. In a document scanner, the documents to be scanned may vary by size, weight, color content, physical condition, or other characteristics, which may require different scanner features to be enabled or operator actions to be employed for the most optimal and efficient mode of operation. Prior knowledge of these many different document attributes can enable the proper selection of scanner features to improve the efficiency of the scanning process or enable other features which may provide specific applications required by a particular type, style, or size of document. Prior knowledge of the documents physical condition can also prompt immediate action from the operator to protect the document or scanner or allow other features within the scanner to perform more reliably.
The exit area of the scanner is used for collecting the scanned documents as they exit the transport. A document must also exit the scanner, once it has been imaged, in an orderly fashion. By discerning document characteristics in the input area as well as the exit area, characteristics such as, but not limited to, number of documents, the exit area features which control stacking and tracking can be managed.
During the scanning process there are a number of ways in which the information extracted from a scanned document may be inaccurate. The scanned document may be deformed or wrinkled by the document transport system, there may be dust or foreign matter on the image capture optics, the document may be skewed or misaligned, or incorrect scanning features may have been selected, but not limited to, all of which may result in capture of inaccurate information during the scanning process. There exists a need to verify captured image data, especially in high speed document scanners.
There have been attempts in the document printing industry to verify information on printed images, but the requirements for printing a document are different than the requirements for accurate scanning of a document.
For example, U.S. Publication No. 2008/0013848, discloses a line-by-line scan of a printed document to check for defects such as streaks or banding in the printed document. U.S. Publication No. 2003/0076518, discloses a printer which incorporates a CCD raster capture device which images the output tray. The captured output image is compared to data used to print the document.